NASA snaps photo of remote planet 25 light years away using visible light spectrum, a first

Posted November 14, 2008 - 01:04
by
Rick C. Hodgin

Earth orbit - NASA's Hubble Space Telescope has taken the first ever visible light picture of a planet in orbit around a distant star. The planet, dubbed Fomalhaut b, is estimated to be three times the mass of Jupiter. It orbits Fomalhaut, some 25 light years from Earth. The star system is in the constellation Piscis Australis, or "Southern Fish." Singing... "When you see the Southern Fish for the first time..."

A continuing effort

NASA's Infrared Astronomy Satellite (IRAS) recorded excessive dust surrounding Fomalhaut in the 1980s. NASA was later able to resolve visible light images (taken by Hubble's High Resolution Camera) of the region around Fomalhaut in 2004. These showed a massive debris field some 21.5 billion miles in diameter, roughly 3x the diameter of our solar system, with a very defined inner edge making it appear like a ring. The field is believed to be comprised of varying size objects, some as small as dust particles, others larger than Pluto.

The ring's defined shape led Hubble astronomer Paul Kalas to propose in 2005 that the sharp inner edge may be gravitationally induced. Once it was proposed there may be a planet there, the hunt was on.

Two years apart

After taking visible light images of the region some 21 months apart, a very faint image showed a clear track of movement. These separate dots are believed to be Fomalhaut b in orbit around its star, with an orbital period of 872 years using Kepler's laws of planetary motion. If true, these faint dots would be the first ever visible light images captured of another planet. Stellar.

Hard work

According to Kalas, "Our Hubble observations were incredibly demanding. Fomalhaut b is 1 billion times fainter than the star. We began this program in 2001, and our persistence finally paid off."

Mark Clampin from NASA's Goddard Space Flight Center, said, "Fomalhaut is the gift that keeps on giving. Following the unexpected discovery of its dust ring, we have now found an exoplanet at a location suggested by analysis of the dust ring's shape. The lesson for exoplanet hunters is 'follow the dust'."

Exploring deeper

Future efforts by NASA will include the use of infrared cameras in the search for water vapor in the atmosphere. If found, this would serve as the first evidence of planetary water outside of our solar system. Such evidence may also yield clues about the age of the planet, now estimated to be 100 million years.

Astronomers will continue to track Fomalhaut B's orbit to more precisely determine the planet's mass.